Pressing F12 with the main browser window focused while the undocked devtools are already open sometimes makes the entire browser crash, I've been unable to reliably reproduce this bug but it happens to me multiple times on a daily basis.

Definitely not extension related as it still happens even with no extensions enabled.

On a related note, something that irks me as a webdev is that pressing F12 with the (undocked) dev tools open but not focused will close the dev tools. In firefox and chrome it brings the dev tools to focus. Minor annoyance but it's very disruptive to workflow...